Multifunctional fuel gas nozzle

ABSTRACT

The present invention discloses a multifunctional fuel gas nozzle such that the nozzle is generally applicable for both natural gas and liquefied gas with different pressures. The multifunctional fuel gas nozzle of the present invention comprises a hollow core, a shell which is tightly jointed to the rear end portion of the core, and a switch strip which is axially movable with respect to the shell. The above structure is always applicable by switching the switch strip whenever the shell is used for natural gas with a lower input pressure or liquefied gas with a higher input pressure. Therefore, natural gas and liquefied gas with different pressures can share the nozzle only by simple adjustment according to the present invention.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a nozzle structure for a burner, and, more particularly, to a multifunctional fuel gas nozzle which is capable of adjustment to fit the user and applicable for liquefied gas or natural gas.

(b) Description of the Prior Art

Humans have used chemical gas as a fuel for more than one hundred years. The most widely used fuels are natural gas with a lower pressure which is delivered by ducts, and liquefied gas with a higher pressure which is transported by cylinders (commonly referred to as drum gas).

Since the input pressures of both described above are different, the gas valves of liquefied gas furnaces require smaller nozzle diameters thereof due to the higher input gas pressure of the liquefied gas filled in cylinders; the gas valves of natural gas furnaces require larger nozzle diameters thereof owing to the lower gas pressure of the natural gas delivered by ducts. Thus, if users hope to change a different kind of fuel gas, the gas valve must be changed in order to fulfill the requirement of such gas for combustion. The change of the nozzles is irreversible so that if the nozzle needs to be changed back, it is necessary to change another burner. Accordingly, this results in a severe waste problem.

To solve the above problem, the valve body and the nozzle were designed to be separated from each other in the prior art. When some kind of fuel gas is used, the nozzle corresponding to the kind of fuel gas is changed. However, the nozzles are of the same configuration and only differ from the nozzle diameters. It is difficult to distinguish the difference between those diameters. Therefore, mistakes are easily made in the manufacturing and changing processes so that these processes must be operated by professionals, and the nozzles cannot be changed by consumers themselves.

For the convenience of changing different nozzles on the same furnace burner by consumers themselves, there were two nozzles with two different diameters designed on the same gas valve in such a manner that the nozzle with a larger hole is located inside and the nozzle with a smaller hole is located outside. If the liquefied gas in cylinders is used, the nozzle can be directly employed without any adjustment; if the in-duct natural gas is used, the larger hole can act only by removing the outside nozzle with the smaller hole.

While this adjusting method is simple and convenient and can be operated by consumers themselves, the volume of the removed nozzle is very small so that it is inconvenient to be stored and easy to be lost. If the nozzle is to be changed back, the consumers must often face the difficulty of installation or the loss of the nozzle.

In the prior art, there was a method which utilizes a switching slide to change the nozzles with different diameters. According to the technique of the prior art, a switching slide is disposed between a switching nozzle and a switching chassis, and said slide is provided thereon with fuel gas inlet of two or more diameters. Furthermore, an O-ring seal is disposed between the switching chassis and the switching slide for sealing purpose.

When a fuel gas inlet is changed into one of a different diameter, purpose of exchange of these inlets can be achieved as long as the slide is driven to align the gas inlet of the slide with the gas outlet of the chassis. However, according to the technique, at least two kinds of gas inlets of different diameters must be disposed on the slide, so that the length of the slide is too long with respect to that of the entire nozzle, thus increasing the nozzle volume. Besides, when in use, the nozzle temperature rises very high due to the combustion in the burner such that the O-ring seal would age or melt rapidly at such a high temperature and lose its sealing function, which may cause the leakage of fuel gas and a serious hazard.

SUMMARY OF THE INVENTION

A technical problem that the present invention has been made to solve in view of the present technical situation is to provide a multifunctional fuel gas nozzle, which is applicable for liquefied gas or natural gas without removal or addition of any parts, only by simple adjustment.

Another technical problem that the present invention has been made to solve in view of the present technical situation is to provide a multifunctional fuel gas nozzle with excellent gas tightness, long life span and a compact volume.

In order to solve the above-mentioned problems, according to the technical solution of the present invention, there is provided the multifunctional fuel gas nozzle comprising a hollow core, on the top of which a liquefied gas hole is disposed;

a shell, within which the core is located, the rear end portion of the core being fastened to and tightly jointed to the shell, the front end portion of the core and the shell defining a definite clearance therebetween and the core being provided thereon with a lateral aperture;

a switch strip, which is disposed within said shell, in front of the core and is axially movable with respect to the shell, the shape of the rear end portion of the switch strip matching that of the front end portion of the core, when the switch strip and the core are closely attached to each other, both of them are tightly jointed to each other; a natural gas through hole being disposed at the position on the switch strip corresponding to the liquefied gas hole, the sum of the cross-sectional area of the liquefied gas hole and that of the lateral aperture being larger than or equal to the cross-sectional area of the natural gas hole; besides, a force application portion, which is disposed on the front face of the switch strip in favor of moving the switch strip; and a stopping portion, which is disposed in front of the shell to prevent the switch strip from coming off the shell.

When the shell is connected to the liquefied gas supply, the switch strip is moved such that the recess at the rear end thereof is closely attached to the front end of the core. The natural gas hole on the switch strip and the liquefied gas hole on the core would mate together at this time, and only the liquefied gas hole acts and can meet the flow volume and velocity as required by a liquefied gas furnace burner.

If it is desired to use natural gas, the switch strip is moved such that the switch strip and the core are separated by a distance. The liquefied gas hole and the lateral aperture on the core would evolve gas simultaneously at this time, and the final flow volume blown off from the nozzle is controlled by the natural gas hole on the switch strip. Thus, it is very convenient to switch between different gas species for combustion. Besides, the front end of the shell is provided with the stopping portion which prevents the switch strip from coming off the shell. Therefore, no matter how the switch strip is moved, the switch strip would not come off the shell, thereby avoiding the loss of the switch strip.

In the implementation of the present invention, said shell can be designed to be hollow and cylindrical, and the switch strip joins the shell with high precision threads. Accordingly, it is convenient to adjust the position of the switch strip on the shell, and a good sealing of the nozzle is also achieved by avoiding the use of the seal members made of the materials such as plastics or the like and the aging thereof.

The front end portion of said core can be conical and said lateral aperture can be disposed on the conical surface of the cone; the rear end portion of said switch strip is provided thereon with a recess which matches the front end portion of the core; the front end portion of said core can also be cylindrical, and said lateral aperture is disposed on the side surface of the cylinder.

When the front end portion of said core is cylindrical, said lateral aperture can also be disposed on the top surface of the cylinder. At this time, the back face of said switch strip is flat. When the switch strip is tightly attached to the core, the switch strip covers the lateral aperture.

The number of the lateral apertures is at least 1 and has relations with the size of the lateral apertures as long as the sum of the flow volume through the lateral apertures and through the natural gas holes meet the requirements of a natural gas furnace burner.

Said stopping portion can be located on the front face of the shell or on the inside flange; it can also be located in front of the switch strip, on the side surface inside the shell and be without turned threads.

The inside diameter of the portion, which is located on the top of the side surface inside the shell and is without threads, is less than the outside diameter of the thread of the switch strip. Accordingly, when the switch strip is screwed to the limit position at the front end of the shell, it will stop due to no thread at all, so that it will not come off the shell. This structure is simple, convenient and practical.

Said core and said shell are fastened to and tightly jointed to each other, and they can be threadedly jointed to each other in favor of product assembly and capable of achieving the requirement for sealing. In order to ensure a definite clearance remained between the front end portion of the core and the shell and no need of a particular design of the core shape, a valve body can be added between the rear end portion of the core and the shell such that any two of the rear end portion of the core, the valve body and the shell are tightly jointed to each other, and they can be threadedly jointed to each other.

Said force application portion can be disposed on the front face of the switch strip in favor of turning the groove of the switch strip using a screwdriver or an inner hexagonal spanner, or the like. Said groove can be a “cross” groove or a “straight” groove which matches a straight head screwdriver or a crosshead screwdriver, and can also be a “hexagonal” groove which matches an “inner hexagonal” spanner. The center of said groove is the center point of the switch strip.

Compared with the prior art, the core and the switch strip are mounted inside the shell, and the stopping portion is disposed at the front end of the shell according to the present invention. Such kind of structure can achieve the purpose of conveniently and rapidly adjusting the nozzle diameter by users themselves while it can also prevent the switch strip from coming off the shell, which results in the loss of the switch strip. Furthermore, the switch strip, the core and the stopping portion are tightly jointed to one another with high precision so that it is unnecessary to use sealing materials, thus simplifying the nozzle structure. It is more important that the defects of melting and aging of the sealing materials due to the use of them such as rubber or plastics or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become apparent from the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic view showing a structure according to the present invention.

FIG. 2 is a three dimensional view of a core according to the present invention.

FIG. 3 is a side view of a switch strip according to the present invention.

FIG. 4 is a schematic view showing one service condition of liquefied gas according to the present invention.

FIG. 5 is a schematic view showing one service condition of natural gas according to the present invention.

FIG. 6 is schematic view showing a structure of a core according to a second embodiment of the present invention.

FIG. 7 is schematic view showing a structure of a core according to a third embodiment of the present invention.

FIG. 8 is schematic view showing a structure of a switch strip according to a second embodiment of the present invention.

FIG. 9 is schematic view showing a structure of a switch strip according to a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIG. 1, a multifunctional fuel gas nozzle according to the present invention comprises a shell 20, a hollow core 10 connected to the fuel gas supply, and a switch strip 30.

Wherein, as illustrated in FIGS. 1 to 4, said core 10 is a hollow part, the rear end of which is a cylinder with a turned thread on its surface, and the core is fastened to a valve body 40 via the thread and fastened to the rear end portion of the shell 20 through the thread of the valve body 40. The shape of the front end portion 13 of the core 10 is conical, and a liquefied gas hole is disposed on the top surface of the cone to meet the requirements in use of liquefied gas as a fuel; a lateral aperture 12 is disposed on the conical side surface of the front end portion 13, and the sum of the cross-sectional area of the lateral aperture 12 and that of the liquefied gas hole 11 must satisfy the requirements in use of natural gas as a fuel, that is, the sum of the flow volume through the lateral aperture 12 and that through the liquefied gas hole 11 must satisfy the requirements in use of natural gas as a fuel.

In the implementation of this embodiment, if necessary, two, three, or even more lateral apertures 12 can be disposed depending on the size of the lateral apertures 12 as long as the sum of the flow volume through these apertures and that through the liquefied gas hole 11 can satisfy the requirements in use of liquefied gas as a fuel. As illustrated in FIG. 6, said lateral aperture 12 can be disposed on the side surface of the middle portion of the core 10.

As illustrated in FIG. 7, when the front end portion 13 of the core 10 is cylindrical, said lateral aperture 12 can be disposed on the cylindrical top surface. In accordance with the shape of the core 10, the rear end portion of the switch strip 30 could be provided with no recess as long as provided thereon with a natural gas hole 31 which passes through the switch strip 30.

As illustrated in FIGS. 1 and 3, said switch strip 30 is cylindrical, the cylindrical surface of which is turned with threads and the rear end of which has a recess which matches the front end portion 13 of the core 10. When the recess 33 is attached to the front end portion 13, both of them are tightly jointed to each other. The natural gas hole 31 is disposed at the center on the front face of said switch strip 30 to satisfy the requirements in use of natural gas as a fuel. The switch strip 30 is provided on the front face thereof across the center with a force application portion 32. The force application portion 32 can be a “straight” groove in favor of moving the switch strip 30 using a straight head screwdriver.

As illustrated in FIG. 8, the front face of the switch strip 30 can be provided with a groove as the force application portion 32 in favor of using a crosshead screwdriver; or as illustrated in FIG. 9, provided with a “hexagonal” groove in favor of using an “inner hexagonal” spanner.

As illustrated in FIGS. 1 and 4, said shell 20 is hollow and cylindrical, the female threads of which, the male threads of the switch strip 30 and the male threads of the valve body 40 are all high precision ones fitted with each other to fulfill the requirement of gas tightness. The female threads of the shell 20 are not disposed over the entire inner surface thereof, and a part of the top thereof without turned threads serves as a stopping portion 21 to prevent the switch strip 30 from being screwed beyond the shell 20 when adjusting the position of the switch strip 30.

In assembly, the switch strip 30 and the core 10 are first screwed in the shell 20, and then the shell 20 is screwed in the corresponding position of the valve body 40, as shown in FIG. 8. When the valve body 40 supplies liquefied gas as the fuel, a screwdriver or a spanner is put in the force application portion 32 to screw the switch strip 30 such that the recess 33 at the rear end thereof is attached to the cone of the front end portion 13 of the core 10. The liquefied gas hole 11 on the core 10 and the natural gas hole 31 on the switch strip 30 would mate together at this time. After the switch strip 30 is tightened, the recess 33 thereof would match up the conical surface of the front end portion 13 to achieve the requirement of tight attachment while it could block up the lateral aperture 12. Therefore, only the liquefied gas hole 11 on the core 10 acts at this time so that the liquefied gas furnace is operated in the normal combustion status.

As illustrated in FIG. 5, the furnace can be switched to use natural gas as long as the switch strip 30 is screwed off the front end portion 13. When the switch strip 30 is screwed to the top of the shell 20, the stopping portion 21 without turned threads is disposed on the top of the shell 20 so that the switch strip 30 would not come off the shell 20. At this time, the liquefied gas hole 11 and the lateral aperture 12 evolve gas simultaneously, and the gas passes through the recess 33 on the switch strip 30 and enters the natural gas hole 31. The final flow volume is controlled by the natural gas hole 31 so as to achieve the requirement of the natural gas furnace operated in the normal combustion status.

What has been described above is the preferred embodiment of the present invention only, it is not intended to limit the scope of the present invention. Various equivalent changes and alternatives to the present invention can be made to the elements of the present invention without departing from the spirit and scope of this invention. Accordingly, all such equivalent changes and alternatives should be included within the scope of the appended claims. 

1. A multifunctional fuel gas nozzle comprising: a hollow core, on the top of which a liquefied gas hole is disposed; a shell, within which the core is located, the rear end portion of the core being fastened to and tightly jointed to the shell, the front end portion of the core and the shell defining a clearance therebetween and the core being provided thereon with a lateral aperture; a switch strip, which is disposed within said shell, in front of the core and is axially movable with respect to the shell, the shape of the rear end portion of the switch strip matching that of the front end portion of the core, when the switch strip and the core are closely attached to each other, both of them are tightly jointed to each other; a natural gas through hole being disposed at the position on the switch strip corresponding to the liquefied gas hole, the sum of the cross-sectional area of the liquefied gas hole and that of the lateral aperture being larger than or equal to the cross-sectional area of the natural gas hole; a force application portion, which is disposed on the front face of the switch strip in favor of moving the switch strip; and a stopping portion, which is disposed in front of the shell to prevent the switch strip from coming off the shell.
 2. The multifunctional fuel gas nozzle according to claim 1, wherein: said shell is hollow and cylindrical, and the switch strip joins the shell with high precision threads.
 3. The multifunctional fuel gas nozzle according to claim 1, wherein: the front end portion of said core is conical and said lateral aperture is disposed on the conical surface of the cone; the rear end portion of said switch strip is provided thereon with a recess which matches the front end portion of said core.
 4. The multifunctional fuel gas nozzle according to claim 1, wherein: the front end portion of said core is cylindrical, and said lateral aperture is disposed on the top surface of the cylinder, and the back face of said switch strip is flat, when the switch strip is tightly attached to the core, the switch strip covers the lateral aperture.
 5. The multifunctional fuel gas nozzle according to claim 1, wherein: said stopping portion is disposed at the front end portion of the shell.
 6. The multifunctional fuel gas nozzle according to claim 5, wherein: said stopping portion is composed of the portion, which is located in front of the switch strip, on the side surface inside the shell and is without turned threads.
 7. The multifunctional fuel gas nozzle according to claim 6, wherein: the inside diameter of the portion, which is located on the top of the side surface inside the shell and is without threads, is less than the outside diameter of the thread of the switch strip.
 8. The multifunctional fuel gas nozzle according to claim 1, wherein: said force application portion is disposed on the front face of the switch strip in favor of turning the groove of the switch strip using a screwdriver.
 9. The multifunctional fuel gas nozzle according to claim 8, wherein: the center of said groove is the center point of the natural gas hole. 